A clock made from strontium atoms and lasers has become the world's most stable and precise timekeeper.

The experimental timepiece is an atomic clock that uses lasers to link the length of a second to the frequency of light that makes electrons in strontium atoms jump to a higher energy level. The new clock, described January 23 in Nature, is about 50 percent more precise than the previous record holder made of a single charged aluminum atom, and it rivals the ytterbium atomic clock for the title of most stable.

The clock will improve physicists’ definitions of the standard units of measure in the metric system and test of the fundamental laws of nature, the team writes.